It rises from Lake Matese and in the first part of its way, it is characterised by cascades and differences in heights.

On its shores violets grew, and this is why the Greeks called it Clanis. The River Clanis rises on Mounts Tifatini.

It rises at the foot of Mounts Trebulani, at 86 meters above sea level, in the territory of Calvi Risorta.

In the north-east of Campania Felix, separated from the Campania Apennines by the valley of the Medio Volturno, the massif of the Trebulani Mountains rises, also known as the Colli Caprensi.

Although its name derives from the Oscan word tifata, which means holm oak, Mount Tifata is largely barren, except for the woods surrounding the northern side.

For the ancients, it was the river of the myth, which gave forgetfulness to whoever drunk its water.